But, at the same time, a BMW dealer sold me the update USB which clearly states it should work on my 335. But alas, it does not.

Up to this point in my life, I didn't think Germans were this sloppy. Anyone have perspective on what is going on?

Do the product people at BMW know what they are doing? Seems like incompetence.

Do you have a newer firmware on the iDrive? I think for some people with 09/10 models, if they have their firmware updated before by BMW, then the USB maps will work.

My dad has an 2009 BMW early Apr/09 build. I've tried to do the USB update from the 09 maps straight to the 13 maps, and it doesn't work. I plugged it into the USB in the glove box, and the USB only flashes a few times, and it stops flashing and nothing happens. Even after waiting a few minutes, still nothing happens. The USB is formatted to FAT32, with only the 2 files in the "root" folder. No luck...

The firmware on his car hasn't been updated before.. It'll be a trip to the dealer, like a few other people have experienced.